=over

=item $OSNAME

=item $^O
X<$^O> X<$OSNAME>

The name of the operating system under which this copy of Perl was
built, as determined during the configuration process.  For examples
see L<perlport/PLATFORMS>.

The value is identical to C<$Config{'osname'}>.  See also L<Config>
and the B<-V> command-line switch documented in L<perlrun|perlrun/-V>.

In Windows platforms, C<$^O> is not very helpful: since it is always
C<MSWin32>, it doesn't tell the difference between
95/98/ME/NT/2000/XP/CE/.NET.  Use C<Win32::GetOSName()> or
Win32::GetOSVersion() (see L<Win32> and L<perlport>) to distinguish
between the variants.

This variable was added in Perl 5.003.

=back